1. Field of the Invention
This invention is directed to a power-driven screwdriver for use with a strip of screws.
2. Prior Art
It has been known heretofore to secure plasterboard by nails or screws, screws being preferable. In doing so, the tradesman selects a screw carried in a pocket of an apron that he wears, and holds such screw in position by hand. It has then been known to use a power-driven screwdriver to advance the same to secure the plasterboard on the wall or on the ceiling of a room. Under such conditions, it has not been uncommon to drop a screw. Frequently, it is uneconomic to stop work to retrieve such dropped screw. The workman may be working on stilts or may be on a scaffold near the ceiling, and at any event, his labor rate is such that the practice prevailing today is not to pick up any dropped screw. One realistic estimate is that 15 percent of the screws are dropped and not retrieved. Further, screws can fall from the apron, and the screw loss from all causes is not negligible.
Another difficulty with such type of tradesman activity is that the screw has sharp threads in that it is self-tapping and therefore, the tradesman gets sore fingers.
Further, using the technique described above, an average production rate for an experienced workman is to use about 5 seconds for each screw applied.
Further, to practice the technique described above, with one hand holding the screw, the other hand is used to hold the power screwdriver which, at least, is awkward, due to its length.
Further, using the technique described above, there is frequently a lack of precision in perpendicularity which tends to possibly make work look unprofessional or possibly be weaker than it should be, and this problem also adversely affects the life of the screwdriver bit.
Further, under the technique described above, using power apparatus, it is not always possible to have reliability in the control of the depth that the screw is applied.